Re: [PATCH v5 01/14] block: return status from bdrv_append and friends

[Alberto Garcia]

On Sat 09 Jan 2021 01:57:58 PM CET, Vladimir Sementsov-Ogievskiy wrote:
> -void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
> +int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
>                           Error **errp)

The indentation of the second line should be adjusted, shouldn't it?

>  {
> +    int ret;
>      bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
>          bdrv_inherits_from_recursive(backing_hd, bs);
>  
>      if (bdrv_is_backing_chain_frozen(bs, child_bs(bs->backing), errp)) {
> -        return;
> +        return -EPERM;
>      }
>  
>      if (backing_hd) {
> @@ -2853,15 +2854,24 @@ void bdrv_set_backing_hd(BlockDriverState *bs, 
> BlockDriverState *backing_hd,
>
>      bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_of_bds,
>                                      bdrv_backing_role(bs), errp);
> +    if (!bs->backing) {
> +        ret = -EPERM;
> +        goto out;
> +    }

This is not visible in the patch, but before the bdrv_attach_child()
call there's this:

    if (!backing_hd) {
        goto out;
    }

But in this case 'ret' is still uninitialized.

>  out:
>      bdrv_refresh_limits(bs, NULL);
> +
> +    return ret;
>  }



> -static void bdrv_replace_node_common(BlockDriverState *from,
> -                                     BlockDriverState *to,
> -                                     bool auto_skip, Error **errp)
> +static int bdrv_replace_node_common(BlockDriverState *from,
> +                                    BlockDriverState *to,
> +                                    bool auto_skip, Error **errp)
>  {
>      BdrvChild *c, *next;
>      GSList *list = NULL, *p;
> @@ -4562,6 +4572,7 @@ static void bdrv_replace_node_common(BlockDriverState 
> *from,
>              goto out;
>          }
>          if (c->frozen) {
> +            ret = -EPERM;
>              error_setg(errp, "Cannot change '%s' link to '%s'",
>                         c->name, from->node_name);
>              goto out;

Same here, you set 'ret' in the second 'goto out' but not in the first.

Berto